Before the present invention, several kinds of benzoyl urea compounds have been developed as an inhibitor for chitin formation. As typical examples commercially available, N-(2,6-difluorobenzoyl)-N'-(4-chlorophenyl)urea described in U.S. Pat. No. 3,933,908 and N-(2,6-difluorobenzoyl)-N'-(3,4-dichlorophenyl)urea described in U.S. Pat. No. 4,166,124 can be mentioned, which were the initiation of the developments of benzoyl urea-based pesticides.
European Patent Publication Nos. 093,976 and 093,977 disclose aryl benzoyl urea derivatives having a similar structure to the desired compound of the present invention. However, they are different from the compound (I) of the present invention in that all the substituents of R.sup.2, R.sup.3 and R.sup.4 are some groups other than hydrogen, or R.sup.3 position is substituted with an ether group. Furthermore, their pesticidal spectrum is restricted to Plutella. And compounds with good pesticidal activity among them are mainly benzoyl ureido diphenyl ether derivatives, which can be prepared only through complicated and uneconomic processes.
In addition, European Patent Publication No. 232,080 discloses benzoyl urea derivative of which aryl moiety is 2,5-difluoro-4-chlorophenyl. However, since LC.sub.50 thereof against Spodoptera is 0.3 to 0.4 ppm, it has a much lower activity than the compound according to the present invention having 0.1 ppm or less of LC.sub.50 against the same pest.
While, International Patent Application No. PCT/KR95/00072, which was filed by the present applicant, discloses phenyl benzoyl(nicotinoyl) urea derivatives wherein R.sup.3 position is fixedly substituted with hydrogen, which is different from the compound of the present invention wherein R.sup.3 position is substituted with halogen or cyano. Further, with respect to the pesticidal activity against both Plutella xylostella and Spodoptera litura, the compound of the present invention is superior to that described in the International Patent Appln. No. PCT/KR95/00072.